On Tue, Mar 04, 2025 at 11:56:50AM -0500, Connor Abbott wrote:
> Up until now we have only called the set_stall callback during
> initialization when the device is off. But we will soon start calling it
> to temporarily disable stall-on-fault when the device is on, so handle
> that by checking if the device is on and writing SCTLR.
>
> Signed-off-by: Connor Abbott <cwabbo...@gmail.com>
> ---
> drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 30
> +++++++++++++++++++++++++++---
> 1 file changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> index
> a428e53add08d451fb2152e3ab80e0fba936e214..d34a0d917013bb3d5a24b3ce72f48e3b38474da2
> 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> @@ -77,12 +77,36 @@ static void qcom_adreno_smmu_set_stall(const void
> *cookie, bool enabled)
> {
> struct arm_smmu_domain *smmu_domain = (void *)cookie;
> struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
> - struct qcom_smmu *qsmmu = to_qcom_smmu(smmu_domain->smmu);
> + struct arm_smmu_device *smmu = smmu_domain->smmu;
> + struct qcom_smmu *qsmmu = to_qcom_smmu(smmu);
> + u32 mask = BIT(cfg->cbndx);
> + bool stall_changed = !!(qsmmu->stall_enabled & mask) != enabled;
> + unsigned long flags;
>
> if (enabled)
> - qsmmu->stall_enabled |= BIT(cfg->cbndx);
> + qsmmu->stall_enabled |= mask;
> else
> - qsmmu->stall_enabled &= ~BIT(cfg->cbndx);
> + qsmmu->stall_enabled &= ~mask;
> +
> + /*
> + * If the device is on and we changed the setting, update the register.
> + */
> + if (stall_changed && pm_runtime_get_if_active(smmu->dev) > 0) {
> + spin_lock_irqsave(&smmu_domain->cb_lock, flags);
> +
> + u32 reg = arm_smmu_cb_read(smmu, cfg->cbndx, ARM_SMMU_CB_SCTLR);
> +
> + if (enabled)
> + reg |= ARM_SMMU_SCTLR_CFCFG;
> + else
> + reg &= ~ARM_SMMU_SCTLR_CFCFG;
> +
> + arm_smmu_cb_write(smmu, cfg->cbndx, ARM_SMMU_CB_SCTLR, reg);
Are you sure you don't need TLB invalidation for this to take effect? I
think some fields in the SCTLR can be cached in the TLB but you'll need
to check whether or not that applies to CFCFG.
Will
